Vacuum cup type holding devices are widely used in industry to grip and hold parts during transfer, manufacturing, assembly, and other operations. It is common practice to obtain the necessary vacuum by flow of high pressure air through a vacuum creating device. In some uses of such devices, it is necessary or desirable to be able to quickly and reliably release the parts and one of the problems of prior art devices has been a failure to provide quick and reliable release of the parts.
It is a primary objective of the present invention to provide a new and improved vacuum control system in which a vacuum condition and a non-vacuum condition are positively, reliably, and quickly established by merely stopping and starting air flow through a vacuum creating device. To this end, new and improved vacuum control means have been associated with a vacuum creating device in a new and improved manner. In the presently preferred embodiment of the inventive concepts, the vacuum control means comprises a vacuum forming member movable by the presence or absence of high pressure air between a vacuum forming position and a non-vacuum position. The vacuum forming member is moved to a vacuum forming position when connected to a high pressure air source and is held in that position as long as it is connected to that source. A return means is independently rendered operable by the high pressure air and is operationally independent of the vacuum forming member until disconnected from the high pressure air source whereupon the return means is immediately effective to move the vacuum forming member from the vacuum forming position to the non-vacuum position. In addition, positive vacuum dissipating means are associated with the movable vaccuum forming member and rendered operable immediately upon initiation of movement of the member toward the non-vacuum position to obtain quick and reliable release of parts held by vacuum.